1. Field of the Invention
The present invention relates to a solenoid-operated valve for discharging a reaction gas and/or residual water from fuel cells of a fuel cell system.
2. Description of the Related Art
Solid polymer membrane fuel cell devices have a stack of cells each comprising a solid polymer electrolyte membrane sandwiched between an anode and a cathode that are disposed one on each side of the solid polymer electrolyte membrane. For operating such a stack of cells, hydrogen is supplied as a fuel to the anode and air is supplied as an oxidizing agent to the cathode. Hydrogen ions are generated at the anode by a catalytic reaction, and move through the solid polymer electrolyte membrane to the cathode where they cause an electrochemical reaction to generate electric power.
A fuel cell system including the above stack has an air compressor for supplying air as a reaction gas to the cathodes and a pressure control valve for supplying hydrogen as a reaction gas to the anodes under a pressure depending on the pressure of the air that is used as a signal pressure. In the fuel cell system, the pressure of the reaction gas supplied to the anodes with respect to the pressure of the reaction gas supplied to the cathodes is adjusted to a predetermined pressure for thereby achieving a predetermined power generation efficiency, and the flow rates of the reaction gases supplied to the fuel cell stack are controlled to obtain a desired fuel cell output.
Japanese Laid-Open Patent Publication No. 2004-183681 discloses a discharge valve for discharging a reaction gas and/or residual water from fuel cells, the discharge valve being disposed at an appropriate position in either an air discharge passage interconnecting an air discharge port and an air discharger or a passage between a hydrogen discharger and a hydrogen discharge port.